One type of surgical access device is commonly referred to as a trocar. Typically, the term “trocar” is used to describe a combination of a cannula, a cannula seal housing, and an obturator. The obturator is a penetrating instrument typically associated with the cannula and inserted through the seal housing and into the lumen of the cannula to expose a penetrating tip of the obturator at the distal end. The cannula seal housing operates to maintain pneumoperitoneum pressure while instruments are inserting into the lumen of the cannula and into the abdominal cavity. The terms “access port” and “access device” are also used to refer to a trocar.
Advances in laparoscopic or minimally invasive surgery have placed new demands on access devices. Because of the increasing complexity of surgical procedures now performed laparoscopically, as well as developments in the instrumentation used in such procedures, improvements, upgrades, and/or redesigns of presently available access devices are desirable. For example, in the early years of laparoscopy, laparoscopic cholecystectomy was considered a complex procedure, which typically included placing three to five access ports and using about three different instruments. Now, laparoscopic cholecystectomy is considered routine surgery and even performed using a single incision in the patient's umbilicus. Other laparoscopic procedures include more complex surgery of the intestine, stomach, lung, uterus, spleen, liver, etc. Instruments specifically developed for such procedures are often complex and asymmetrical, and may include, for example, undercuts, side openings, and sharp regions that can damage and/or destroy a trocar seal. Procedures in which a wide range of instrument sizes are inserted through an access port produce additional issues. For instance, in some procedures instrument diameters range from about 4.5 mm to over about 15 mm. In such procedures, maintaining pneumoperitoneum pressure as small instruments are moved within a region of the seal system designed to accommodate larger instruments is challenging. Also, complex instrumentation requires more space for manipulation and a greater range of motion inside and outside the patient.
Furthermore, access ports placed in a patient may have a tendency to flop around when no instrument is inserted and consequently, when a surgeon attempts to insert an instrument into the access port, the opening of the access port is not in the appropriate position, thereby, necessitating realignment or repositioning of the access point. Other areas for improvement include constructs that secure the seal and prevent it from tearing or overlapping when instruments are inserted and removed. The present invention provides a new and improved trocar that meets these needs.